The rodent ovary contains the microsomal monooxygenases capable of metabolizing polycyclic aromatic hydrocarbons to reactive intermediates. The polycyclic aromatic hydrocarbons; benzo(a)pyrene, 3-methylcholanthrene and 7,12-dimethyl-benz(a)anthracene destroy primordial oocytes in the rodent ovary in a time, dose and metabolism dependent manner. The goal of this research is to explore the relationship between ovarian metabolism of xenobiotic compounds and effects on reproductive performance.